1. Technical Field
The invention is related to audio user interfaces, and more particularly to an audio user interface (UI) for comparing and selecting among multiple audio streams.
2. Background Art
The use of visual user interfaces with small devices such as portable audio and media players, cell phones, and Microsoft Corporation's Smart Personal Object Technology devices is problematic. These types of devices have very small display screens, or no screens at all. As such, a user cannot reasonably rely on visual user interfaces to perform many tasks.
One of the tasks associated with the aforementioned devices involves selecting an audio stream from a number of candidate streams. In order to make a selection, the user often has an existing selection which they want to compare to new candidate selections to make a decision between them. For example, when a user is selecting a station on a radio, often they are comparing the new station to their previous station. Current approaches to these comparison and selection tasks can be said to fall into two categories.
The first approach is simply channel changing, where the user switches to a new audio stream (for example, pressing a preset on the radio or pressing the scan button). However, this approach has some drawbacks. First, it is very slow. Each possible channel has to be previewed individually. Second, the user has no way of comparing their current selection to the new selection. Third, the user has no way of knowing what is coming up—if the next station will be better or worse.
The second approach is to use a textual display to provide information. For instance, a MP3 player can provide a list of songs for the user to select, or an internet radio can provide the names of the stations. This also has problems. Most glaring is that the user has to make the connection between the displayed text and the nature of the audio stream. A song title might suffice is the user is familiar with the song, but the name of the radio station is less informative, as is the name of song not known the user. Granted, more information could be displayed. However, many modern MP3 players are designed to be quite tiny and cannot support a large screen. Thus, the amount of information that can be shown to the user is extremely limited. In addition, the number of alternative selections that can be shown to the user is similarly limited when the display is small. Another disadvantage of the textual display approach is that there are times where it is inappropriate to look at the screen. For example, when one is jogging, riding a bike, or driving a car.
One possible solution is to employ a 3D positional audio user interface to accomplish the comparison and selection tasks. 3D positional audio is an existing technology [see Goose, S and Moller C., “A 3D Audio Only Interface Web Browser: Using Spatialization to Convey Hypermedia Document Structure”, ACM Multimedia (1) 1999: 363-371]. It allows sound to be positioned in space programmatically. In essence, a 3D audio system mixes and filters sound into two or more speakers in such a way as to fool the brain into thinking the sound is located at a particular location external to the user. The present invention employs this approach.